About 1.8 million people die annually from acute diarrheal disease globally. A nationwide cross-sectional survey was conducted via face-to-face interview with eligible subjects to determine the incidence and health seeking behavior of Malaysians with acute diarrheal disease (ADD). An acute diarrheal episode was defined as having three or more loose stools in any 24 hour period during the four weeks period prior to the interview. The exclusion criteria included pre-existing chronic diarrhea, such as with cancer of the bowel, ulcerative colitis or Chrohn’s disease. Forty three point three percent of those with ADD (95% CI 41.3-45.4) sought treatment for the illness. Younger age groups (0-4 years, 67.7%; 95% CI 61.5-73.4; 5-9 years, 56.5%; 95% CI 48.6-64.1) were more likely to seek care for ADD. Seventy-one point eight percent of those seeking treatment, (95% CI 69.0-74.4) did so within 12 hours of the onset of symptoms. Most people with ADD sought treatment at private clinics. The main reasons given for not seeking treatment were the illness was mild and did not warrant treatment and the practice of self-medication (22.4%; 95% CI 20.0-24.9). These findings show self-medication is a major health seeking behavior among Malaysians with ADD. Self-medication of ADD deserves more in-depth study to ensure it is safe.